ICP01 Lecture Course Introduction & The General Structure of Teeth.

1.1 describe the main dental tissues, including the periodontium, and annotate a diagram illustrating them;

Name five functions of teeth?

• Mastication, aesthetics, phonation, jaw guidance during function and tissue support.  

(Jaw guidance and bite would be impacted by restored teeth/missing teeth).  

Label the components of the tooth and explain their role

• Enamel - covers the crown

• Dentine (largest component)  

• Pulp: inner cavity within the crown and root. Apical foramen to allow blood supply.  Pulp chamber – shape/anatomy differ with different tooth types.  

• Cementum: covers the dentine of each root within the jaw  

What are the three names for the anatomical location where crown and root meet?

(1) Cervical line

(2) Crown margin

(3) Crown root margin

(4) Cervical margin

(5) Cemento-enamel junction - CEJ

This is where the crown and cementum meet. 

What is the anatomical vs clinical crown?

• Anatomical = all the tooth covered by enamel. It is a constant height – unless altered by physical wear or attrition.   

• Clinical = visible portion of tooth in mouth (above gingival margin). Height is determined by location of marginal gingiva/free gingiva (can be affected by gingival recession).  

What are the structural components of a crown?

• Incisal edges (incisors and canines only) 

• Cusps (rounded prominence) and ridges (linear elevation) -like mountain/peaks 

• Pits (depression/point like hollow) and fissures (long/narrow groove) - like valleys. Fissures are key risky regions for bacteria to gather and location for caries.  

How many roots does an incisor tooth have?

Both maxillary and mandible incisors have a single root.

How many roots does an canine tooth have?

Both maxillary and mandible canines have a single root.

How many roots do pre-molar teeth have?

1st Pre-molar (4s) in Maxilla have 2 roots and the in the mandible they have 1 root.

2nd Pre-molars (5s) both the maxilla and mandible only have 1x root.

Why:
>Development: During early tooth growth, the tissue sheath for the first premolar naturally pinches and splits into two distinct channels, whereas it usually stays fused as one single root for the second premolar.

>And Force Distribution: The first premolar has a sharp, uneven bite surface that creates heavy lateral (side-to-side) stress, requiring two roots for stability. The second premolar has a flatter, more even surface that experiences mostly vertical pressure, which a single root can safely handle.